6Î-]'Îbu!ªb b facbè flow accelerated corrosionbé1f 2.o b+...
TRANSCRIPT
2007 10
FAC Flow Accelerated Corrosion
1
FAC
FAC
PWR FAC
FAC pH Cr
(FAC)
FAC Flow Accelerated Corrosion, Flow Assisted Corrosion FIC FlowInduced Corrosion
2
(FAC) 3
FAC
(FAC) 4
(FAC) 5
Fe3O4
pH
FAC Flow Accelerated Corrosion Flow Assisted Corrosion
(FAC) 6
2.1mm/Surry 21988/09
1mm/cycle(4 )Catawba 21991/11
6San Onofre 31990/07
8Millstone 21991/11
6Millstone 31990/07
Loviisa 21990/05
#1 14Sequoyah 11994/11
18Surry 21986/12
Callaway1999/08
4 12 5DFort Calhoun1997/04
14 7DTrojan1987/06
(FAC) 7
8FAC
Flow
Distance
Fe2+
Conc.
Metal(Fe)
Bulk water
Fe3O4Boundary layer
AVT (1)3Fe + 4H2O = Fe3O4 + 4H2 (1) ( )
Fe2+ (2)Fe3O4 + 2H2O + 2H+ + 2e- = 3Fe2+ + 6OH- (2)
Fe2+ FAC
dm/dt = (D/ ) Cs - Cbulk) = k Cs - Cbulk) (3)dm/dtD Fe2+
( )Cs Fe2+
Cbulk Fe2+
k D/
9(1/2)
10(2/2)
. ( )
275mm
:
45m/s
11
100(Hr)
<5DO2(ppm)
0 0.05, 0.1 0.2 0.35, 0.5N2H4(ppm)
8.9 9.2 9.5 9.8 10pHNH3
25 35 45(m/sec)
70, 100 150 190 220
Cr 0.02 0.25wt%Cr : 2.25wt%
12FAC
FAC
[FAC (mg/cm2/hr)] =
{[ ] – [ ]} { [ ]}
. ( )
( )
13–
FAC 100
FAC500
.
14–
. FAC
FAC
15–
. FAC
FAC 150
16– pH
FAC pHpH9.5
FAC1/10 1/20
FACpH
. FAC pH
17– N2H4
pH FAC N2H4 ppm
. FAC N2H4
18– Cr
Cr 2.25%FAC Cr
0.02% 1/20 1/50
CFAC
. FAC Cr
19FAC
FAC pH
FAC FAC
FAC
20(1/3)
( )
: (NH3, ETA, )
pH FAC FAC
pH
21(2/3)
AVT
Analytical Fe Conc.(ppb)
Calc
ulat
ed F
e Co
nc.(p
pb)
22(2/3)
(ppb)
0.5 12 34 6
1.00.62.14.8
ETANH3
pHETAAVT
23
FAC pH
FAC
PWR SG
SG
FAC
24(FAC)
O.Jonas,"Control Erosion/Corrosion of Steels in Wet Steam",Power, March, p102(1985)
180pH 7 9.5
<5ppb 500ppb20 m/s
pH7pH9.5 DO2 <5ppbpH7 DO2 <5ppb
FAC
FAC
18Cr StainlessFAC
25(FAC)
75pH 7
0 500ppb1.6 m/s
0.5 Mo1Cr-0.5Mo
120pH 7
0 500ppb35 m/s
FAC
FAC
(Fe2O3)
3
FAC
26(1/2)
FAC
FAC
FAC
FAC pH C
FAC 150FAC pH 0.6ppm
27(2/2)
FACFAC